You have to sympathize—almost—with North Korea. Like leaders in China, Iran, and other coastal states, the Kim Jong-un regime hopes to erect a buffer against stronger sea powers operating off North Korean shores. If successful, it will deny them access to these waters outright or elevate the costs of doing business there to unbearable levels. Unlike these countries, North Korea lacks significant political and geostrategic advantages that help it offset the advantages commanded by stronger opponents. The material mismatch separating the DPRK from South Korea and the United States yawns wide. The Korean People’s Army Naval Force, for instance, fields a modest submarine force and a sizable fleet of patrol boats armed with Styx anti-ship missiles. Yet its warships generally hug the nation’s east and west coasts, operating within about a 50-kilometer offshore belt.

That the navy boasts some capability against modern navies became obvious when a North Korean mini-sub sent the South Korean corvette Cheonan to the bottom in 2010. But consider the tactical and operational difficulties confronting North Korean commanders. Like China, but unlike Iran, Pyongyang must disperse finite effort and hardware between multiple, equally important seas. Its navy confronts a bicoastal anti-access problem vis-à-vis the South Korean and U.S. armed forces. Korean War history—a living thing for the leadership by all accounts—rivets minds on maritime defense. The 1950 amphibious landings at Inchon, on the west coast, and Wonsan, to the east, demonstrated the North’s vulnerability to coastal raids or full-blown invasions from the sea. Furthermore, UN forces rained gunfire and bombs on the peninsula from the sea throughout the conflict. In short, Korea lacks the strategic depth of a China or Iran—placing a premium on access denial.

There are a couple of other quirks to North Korean access denial. Here’s one. Like China—but unlike Iran for the moment—North Korea may soon possess a deployable nuclear arsenal. A working bomb would grant Pyongyang the option to threaten South Korea, and U.S. forces forward-deployed in Asia, asymmetrically. How credibly Pyongyang could yoke threats of atomic devastation to anti-access strategy remains to be seen. Would prospective foes believe such an over-the-top brand of deterrence? Here’s another. Most local defenders mount access-denial strategies against remote powers. Local powers attach far more importance to what happens in nearby waters and skies than remote powers do to operating there. Bigger political stakes engage stronger passions—helping coastal states offset the material advantages of stronger but halfhearted opponents.

But this passion mismatch disappears in contests between adjoining states, when both contenders are determined to manage their surroundings. That’s the case between North and South Korea, which affix enormous importance to developments on the same maritime real estate. Pyongyang stands little chance of disheartening Seoul, which cannot withdraw from the field of competition, whereas Beijing or Tehran can hope to dishearten faraway Washington. Geography may not be destiny. But it certainly shapes destiny—and not always in favor of the access denier.